Pull chain snap switch mechanism



July- 21, 1931. w. c. TREGONING PULL CHAIN SNAP SWITCH MECHANISM Filed'Sept. 10, 1930 Faterited .luly

UNITED STATES WILLIAM C. TREGONING, OF WAUWATOSA, WISCONSIN, ASSIG-NOR TCUTLER-HAMMER,

INQ, OF MILWAUKEE, WIECONSITQ,

imam

T FFEQE COB-PQR-A'IIGN GE DELAVJABE PULL CHAIN SNAP SWITOH MECHANE$I4IApplication filed September 10, 1930. Serial No. 480,845.

This invention relates to improvements in ull chain snap switchmechanism, and although not limited thereto the invent-ion moreparticularly relates to electric lamp sockets having my improved switchmechanism applied thereto.

An object of the invention is to improve the details of construction andthe operative characteristics of switches of the aforementioned type.

Another and more specific object is to improve the structural details ofthe cam track and. the stationary and movable contacts associatedtherewith.

Another object is to provide an improved form of combined supportingbracket and wiring terminal member for the switch.

Various other objects and advantages of the invention will hereinafterappear.

The accompanying drawings illustrate certain embodiments of theinvention which will now be described, it being understood that certainfeatures of the invention are susceptible of embodiment in forms otherthan those illustrated without departing from the scope of the appendedclaims.

In the drawings, Figure 1 is a vertical sectional view of a lamp socket.having my improved pull chain snap switch mechanism applied thereto.

Fig. '2 is. top plan view of the devices illustrated in Fig. 1.

Fig. .3 is a perspective view, in separated relation, of the variousparts of the device illustrated in Figs. 1 and 2'.

Fig. 4 is a sectional view illustrating the form or contour of the camtrack as developed on an annular line intermediate the width of thetrack.

Fig. 5 is a view similar to Fig. 1, but showing a modified form ofcontactor, and a different form of supporting and actuating elementstherefor, and

Fig. 6 is a perspective view, in separated relation, of certain of theparts illustrated in Fig. 5.

Referring first. to Figs. 1 ings the numerals 10 and 11 designate,respectively, the lower and upper insulating buttons between theadjacent faces of which to 4 of the drawthe switch mechanism is adaptedto be secured. The upper face of the lower button 10 is provided with acentrally located cylindrical recess 12, around which is formed anannular cam track. Said cam track is of special form, and as shown thesame comrises diametrically opposed pairs 13, 14, 15 and 16 of tracksections. As best illustrated in Fig. i the track sections 18 and 1 1each preferably extend through an are or area of thirty-one degrees; thesections 15 extend through an area of thirtytwo degrees, and thesections 16 extend through an area of eighty-six degrees, thus providinga complete circle.

A pair of identically formed stationary contact members 17 and 18 areprovided, said members having horizontal contact portions 17- and 18adapted to overlie the diametrically opposed track sections 13 and upwarly angled contact portions 17 and 18 adapted to overlie thediametrically opposed track sections 14:. As shown the sections 15 areinclined downwardly from the points of junction thereof with thesections 14, and the sections 16 are inclined upwardly from the pointsof junction thereof with the sections lia -substantially vertical dropsor shoulders 19 being provided between the rounded extremities 20 ofsections 16 and the sections 13. Also as will be noted the high pointsof the track are of equal height and the low points of the track are ofequal depth.

Adapted to traverse the track sections in a step-by-step manner and toengage and disengage the stationary contacts 17 and 18 jointly with asnap action is a bridging contactor 21, which (as shown in Figs. 1 to4i) may comprise a cylindrical rod or roller havin g an intermediateenlargement or 21*. Contactor 2-1 is adapted for driving engagement by amolded insulating block or cylinder 22 having a recess 23 in its lowerend to loosely accommodate the contactor.

The upper surface of said block has formed therein an annularly arrangedgroup of inclined n otches 24', with which the downwardly inclined teeth25 on ratchet plate 26 are adapted for driving engagement upon rotationcfsaid plate in one direction. Ratchet shoulder plate 26 is providedwith a forked lug 27 to be engaged by the end bead of a pull chain, andsaid plate is further provided with a hook-shaped lug 28 which acts as aguard rail for the chain. Ratchet plate 26 is centered by engagement ofits centrally located flanged opening 29 with the spindle 30 formedintegrally with block 22. Also as will be apparent the block 22 isadapted to at all times extend substantial distance into the recess 12for centering by the walls of the latter. Certain of the elements justme tioned are substantially like the correspond ing parts of the switchmechanism described and claimed in my copending application, filed Dec.2, 1929, Serial No. 415,853.

However, it will be noted that l have herein provided a flat punchedinsulating ring or annulus 31, which loosely surrounds the block 22 andits interposed between the contactor 21 and ratchet adapted high pointsof the cam 21 rides down the incli of, thus effectually snuliing orextinguishing any are which might tend to persist between contactor 21and portions 17 and 18 of the stationary contacts. By the simple andGillcient means just described the current-carrying andcurrentinterrrnting capacity of the switch is very greatly increased.Moreover, it is to be noted that in certain portions of the path ofmovement or" contaetor 21 the latter is adapted to engage and lift theannulus 31, whereby the latter may effectively act as a carrier anddistributor of a lubricating medium, such vaseline, for reducing thefriction and wear between the contaetor and the conducting andinsulating portions of its path.

The stationary contacts 1 vided with base portions 1 are located in theplane of the horizontal portions 17 and 18 respectively, of saidcontacts. The base portion 1'? is loiated in a correspondingly shapedrecess in the upper face of button 10, said base portion beingperforated to receive one end of eyelet 32 which is spun thereover, saideyelet also acting to secure the center lamp contact to the oppositeface of said button.

Base portion 18 is located in a similar but slightly deeper recess inthe upper face of button 10, said base portion having superimposedthereon the base portion 34 of a one piece combined bracket and wiringterminal member 34, an eyelet 35 penetrating button 10 and said baseportions 18 and 84 and being upset over the latter to secure said partsin assembled relation.

Alined with and parallel to base portion 34 is a second base portion 34which seats within a recess in the lower face of button 11 and isrigidly secured thereto by an eyelet 36. The bracket 34 is formed of astraight plate 26. This ring 31 is track when contactor ed sections 15thereand 18 are proto fall into engagement with the C and 18 which stripof metal of substantially equal width throughout its length,said striphaving its opposite edges notched at spaced points 34 34 to define anintermediate wiring terminal portion 34 which is bodily twisted in themanner illustrated. Thus the base portions 34 34 of bracket may bepositioned to extend at substantially right angles to a radius of thebuttonslO and 11 while providing for accessible positioning oi wiringterminal portion 34 in a plane substantially parallel to the circumferene of id buttons. Portion 34 is provided with a tapped opening forcooperative engagement by the shank the i151 binding screw 34.

A combined bracket and wiring terminal member 8'? identical inconstruction with that aforedescribed has its base portion 37 securedwithin a suitably shaped recess in but ton l0, by means of an eyelet 38,which likewise serves to secure one side of the base flange 39 of ascrew shell contact 39 to the lower ta: e of button 10, said eyeletproviding an electrical connection between said screw shell and bracketof said base flange being secured to button 10 by means of an eyelet 39"The other base portion 3?" of the bracket is secured within a suitablerecess in the lower face of button 11, as by means of an eyelet 40. Thewiring terminal portion 37 of the bracket, which is bodily twisted asindicated at the notches 32 is tapped to receive the binding screw 3 Thebutton 11 is provided with a cylindrical passage 41 which opens into aslightly larger substantially rectangular recess 42,

which in turn opens into still larger cylindrical recess 4-3 extendingto the lower face of said button. Recess 42 is adapted to receive andrestrain against rotary movenent the substantially rectangular headflange 44 of an eyelet,the tubular portion 45 of said eyelet beingadapted to interiorly accommo date the insulating spindle 30 and toexteriorly accommodate the coiled torsion-compression spring 46. Struckupwardly from the head flange 44 and bent inwardly into verticalparallelism with each other are a pair of lugs 47 which are normallyadapted to project into the passage 41. Either of the openings 4'? inhead flange 44 may be utilized to receive and retain the upwardlyextending end 46 of s ring 46.

lVhen the parts are assembled in the manner aforedescribed, obviously byinserting a screw driver or similar tool into the passage 41 the releasethe same for rotation within the re cess 43, the lugs 47 being adaptedfor engagement by the screw driver to provide for the desired degree ofadjustment of the spring 46.

The buttons 10 as indicated and 11 are suitably recessed generally at4-8 and 49 to accom- 37,the other side head flange may be depressed to.

-The spindle portion 59f of plate 3 formed on said thirty-one degrees,

wardly angled sections modate the interlocking portions and 50 of a pullchain guide bell assembly 50. The details of co istruction of the guidebell 50 and the manner of assembling the same with respect to thebuttons 10 and 11 are fully disclosed in my Patent No. 1,735,305 and further description thereof is deemed unnecessary.

Certain elements of the device illustrated in Figs. 5 and 6 areidentical with the corresponding parts aforedescribed and are given likecharacters f reference. However, in this form of my invention acontactor 51 of different form is employed. Said contactor 51 ispreferably formed from a fiat punched sheet metal member having asubstantially rectangular perforation intermediate the ends thereof,said member being bent to substantially U-shape in cross section wherebyrounded contact-engaging surfaces 51 and 51 are provided. Theintermediate portion of the conta tor is pro ,ed with short upwardlyextending lugs 51 and 51 which bent or bowed apart to accommodatetherebetween the lugs or projections and 52 formed on a relatirelynarrow punched plate 52 of insulating material. The lower end 52 ofplate 52 is adapted to penetrate the perforation within the contactor 51and to project into a passage 53 for centering by the cylindrical wallof the latter,said passage 53 opening into recess 12 as illustrated.

The upper end 52 of plate 52 is adapted to serve as the switch spindle,apunched plate 5% of insulating material having a ccntrally arrangedrectangular opening 5st whereby the same may he slid onto the spindleportion 52 but held against rotation relatively to the latter. Plate 5ais further provided with group of symmetrically arranged openings 5d",the vertical end walls of which are adapted for drivii 7 engagementbythe lugs or teeth 25 of ratchet plate 26 upon rotation of the latter none direction.

52 adapted. to slide within the cylindrical portion of the combinedbearing and spring-tension acjusting member for centering by the latter.

WVhat I claim as new and desire to secure by Letters Patent is:

1. ln pull switch mechanism, in combination, a molded insulating basehaving a substantially cylindrical recess formed centrally in one facethereof, an annular cam traclr face and surrounding said recess, saidtraclr having duplicate sections arranged in diametrically opposed pairssubstantially as follows; depressed horizontal sections each. extendingthrough an of adjacent upwardly angled sections each extending throughan area of thirty-one degrees, adjacent downwardly angled sections eachextending through an of thirty-two degrees, and adjacent 12' eachextending through an area of eighty-six degrees, the high points of saidtrack being of equal height and the low points of sai track being ofequal depth, a diametrically opposed pair of stationary contacts eachhaving integral portions overlying the two adjacent thirtyone degreesections of the track, a relatively narrow bridging contactor having arounded lower surface adapted to slidably engage and disengage saidcontacts jointly with a snap action upon rotation of said contactor,said contactor being spring-biased into engagement with said'track, andsaid downwardly angled thirty-two degree sections of said track beingadaptedto insure substantial forward displacement of said contactorunder the action of the biasing spring when said contactor is disengagedfrom said contacts;

2. In pull switch mechanism, in combination, a diametrically opposedpair of stationary contacts, a contactor adapted for step-bystep rotarymovement to alternately engage and disengage said contactssimultaneously, said contactor comprising a flat punched sheet metalplate having an intermediate substantially rectangular perforation, saidplate being bent to substantially U-shape in cross section, a spindlecomprising a relatively narrow punched plate of insulating material,said spindle having a centering portion thereof extending downwardlythrough the opening in said contactor for driving engagement with thelatter, and ratcheting means cooperating with said spindle to effectintermittent unidirect'onal rotation of the lat- 3. In pull switchmechanism, in combination, a rotatable bridging contactor comprising apunched sheet metal member bent to substantially channel form, saidcontactor having a substantially rectangular opening intermediate theends thereof, a spindle of rectangular cross section, said spindlecomprising a relatively narrow punched plate of insulating materialhaving a shouldered portion bearing against said contactor and acentering portion extending through the opening in said contactor andbeneath the latter, a punched plate of insulating material slidabledownwardly onto said spindle and adapted to rest upon the shoulderedportion of the latter, said plate and said spindle being interlockedagainst rotary movement relatively to each other, said plate having aplurality of symmetrically arranged perforations, and a one-piececombined ratchet plate and chain rail, said ratchet plate having aplurality of teeth struck downwardly at an angle therefrom and adaptedfor driving engagement with the walls of said perforations upon movementof said ratchet plate in a given direction.

4. In pull switch mechanism, in combination, a pair of spaced insulatingbuttons, each of said buttons having a centrally located dependentlypassage extending therethrough, a cam track formed on one of saidbuttons and surrounding the passage through the latter, stationarycontacts overlying portions of said track, a rotatable contactor adaptedfor alternate engagement with and disengagement from said contactsjointly, said contactor consisting of a punched sheet metal member bentto substantially U-shape in cross section, said contactor having asubstantially rectangular opening in its bottom wall intermediate theends thereof, an insulating spindle of substantially rectangular form incross section,

said spindle having a lower end portion extending through said openingand into the passage in said last mentioned button to be centered by thelatter, said spindle having an enlarged intermediate portion adapted tobear against the inner Walls of said contactor for drivingengagement'with the latter, a flat punched plate of insulating materialcarried.

by said spindle and ment with the latter,

having driving engagesaid plate having a plurality of openings, anoscillatable ratchet plate having ratchet teeth adapted for drivingengagement with the walls of said openings upon movement of said ratchetplate in one direction, a bearing member for said spindle positionedinthe passage in the other of said buttons, and acoiled torsion springinterposed between and interlocked with said bearing member and saidratchet plate to normally bias the latter to a given position inof saidinsulating plate.

5. As an article of manufacture, a onepieee combined spindle bearing andspringtension-adjusting member for pull switch mechanism, said memberhaving a tubular portion adapted to interiorly accommodate a spindle andto exteriorly accommodate a torsion spring, said member also having ahead flange of substantially rectangular contour, and a pair ofdiametrically opposed lugs struck upwardly from said flange and inwardlytoward each other to lie in parallel planes at substantially rightangles to the plane of said flange, said lugs acting jointly forengagement a suitable adjusting tool and either of the openingsresulting from formation of said lugs being adapted to receive andretain one end of a suitably formed torsion spring.

6. As an article of manufacture, a combined supporting bracket andterminal plate for electric snap switches, said bracket being formedfrom a metal strip of uniform width throughout its length, the oppositeend portions of said strip being bent into parallel planes to providebase portions alined with each other, said strip being notched onopposite sides thereof adjacent to said base portions, and theintermediate portion of said strip as defined by said notches beingbodily twisted, for the purpose set forth, said intermediate portionhaving a tapped opening for accommodation of a binding screw.

In pull switch mechanism, in combination, a pair of insulating buttons,a plurality of one-piece combined bracket and terminal membersinterposed between and secured to said buttons to support the latter inspaced relation to each other, each of said members being formed from ametal strip of substantially uniform width throughout its length, eachstrip having aligned notches 011 opposite sides thereof at spaced pointsin its length to define an intermediate portion, the end portions of thestrip being bent in a common direction at substantially right angles tosaid intermediate portion, said intermediate portion having a tappedopening therein to accommodate the shank of a binding crew, and saidintermediate portion being twisted bodily at an angle to the normalplane thereof, whereby said end portions may be positioned to extend ina direction at substantially right angles to a. radius of the respectivebuttons while providing for positioning of the intermediate portion in aplane substantially parallel to the circumference of said buttons.

8. As an article of manufacture, a. punched sheet metal member having ahorizontal contact portion and a base portion integral with and locatedin the plane of said contact portion, and a second contact portionintegral with said first mentioned contact portion and partially severedfrom said base portion, said second mentioned contact portion being bentupwardly at an angle to said first mentioned contact portion, the outerside edges of the respective contact portions and the line of bendingtherebetween all extending in directions radial to a common center.

9. In pull chain snap switch mechanism, in combination, a moldedinsulating base having a substantially cylindrical recess formed in oneface thereof, a cam track formed on said face of the base andsurrounding said recess, stationary contacts overlying diametricallyopposed portions of said track, a diametrically arranged bridgingcontactor overlying said track and adapted for engagement with anddisengagement from said contacts jointly, a cylindrical insulatingmember located within said recess and having a portion thereofstraddling said contactor for driving engagement with the latter, ametal ratchet plate cooperatively engaging said in sulating member foreffecting intermittent unidirectional rotation of the latter, and aninsulating ring loosely surrounding said in sulating member andinterposed between said ratchet plate and said contactor to act as anarc shield for the latter.'

10. In pull chain snap switch mechanism, in combination, a moldedinsulating base having a substantially cylindrical. recess formed in oneface thereof, a cam track formed on said face of the base andsurrounding said recess, stationary contacts overlying diametricallyopposed portions of said track, a diametrically arranged bridgingcontactor overlying said track and adapted for engagement with anddisengagement from said contacts jointly, a cylindrical insulatingmember located within said recess and having a portion thereofstraddling said contactor for driving engagement with the latter, ametal ratchet plate cooperatively engaging said insulating member foreffecting intermittent unidirectional rotation of the latter, and aninsulating ring loosely surrounding said insulating member andinterposed between said ratchet plate and said contactor to act as anarc shield for the latter, said ring being normally supported by thehigh portions of said cam track and being displaced therefrom by saidcontactor in certain positions of the latter whereby the ring may alsoact as a distributor of lubricant placed thereon.

11. In pull switch mechanism, in combination, a molded insulating basehaving a substantially cylindrical recess formed in one face thereof, anannular cam track formed on said face and surrounding said recess, thehigh points of said track being of equal height and the low pointsthereof being of equal depth, said track having diametrically opposedsections the corresponding portions of each of which are arrangedsubstantially as follows in a counterclockwise 5 direction, a lowhorizontal portion extending through an area of thirty-one degrees, anupwardly inclined portion extending through an area of thirty-onedegrees, a downwardly inclined portion extending w through an area ofthirty-two degrees, and an upwardly inclined portion extending throughan area of eighty-six degrees, a pair of stationary contacts eachoverlying the first and second mentioned portions of said track L5sections, a relatively narrow contactor extending diametrically acrosssaid track, the contacting surface of said contactor being of curvedform in transverse cross section to insure a constant area ofengagementthereof with said track in all positions of said contactor,ratcheting means for effecting stepby-step unidirectional movement ofsaid contactor, and common spring means for biasing said ratchetingmeans and said contactor, said spring means cooperating with said trackto insure snap movements of said con tactor into and out of engagementwith said stationary contacts.

In witness whereof, I have hereunto subg5 scribed my name.

WILLIAM C. TREGONING.

